Abundance and habitat-suitability relationship deteriorate in fragmented forest landscapes: a case of Adinandra griffithii Dyer, a threatened endemic tree from Meghalaya in northeast India

Cation budgeting was done under 4- and 12-year old terraces at higher elevation of Meghalaya (960 m) in north-east India. Cation addition occurred after burning the biomass arising from the weed and the crop residue prior to cropping. While nutrient removal through weeds was more under 12-year old terrace than under 4-year old one, the reverse was true for that removed by crop. Nutrient deficit, particularly potassium, was obvious under 12-year old terrace. Decline in soil fertility and increase in weed potential are implicated in the reduced crop yield.

This chapter describes floristic changes, particularly in the herbaceous flora, that have occurred during recent years due to the introduction and spread of alien invasive weeds in Meghalaya and other states in north-east India. Factors favouring biological invasions are briefly covered. Some of the worst invasive weeds that have affected human health and the economic status of the tribal populations of the region are presented: Mikania micrantha, Lantana camara, Chromolaena odorata, Ageratina adenophora, Eichhornia crassipes, Galinsoga quadriradiata and Parthenium hysterophorus.

Simple SummaryThis study focuses on sympatric populations of hen harrier (Circus cyaneus) and Montagu’s harrier (Circus pygargus) breeding in mountain heathlands in the NW Iberian Peninsula. These populations have been affected by habitat loss caused by land-use change. Despite the mounting evidence supporting positive relationships between species abundance and habitat suitability, the capacity of ecological niche models to capture variations in population abundance remains largely unexplored. This study shows that habitat suitability predicted from niche models was significantly correlated with the relative abundance for hen harrier and, to a lesser extent, for Montagu’s harrier. However, the temporal variation in local population abundance was not significantly explained by habitat suitability changes predicted by the niche models. These findings call for caution in the use of niche models to infer changes in population abundance. The positive relationship between species abundance and habitat suitability supports the use of niche models to estimate abundance but does not guarantee the ability of these models to predict temporal variations in species abundance. These findings highlight (1) the need to include other possible biotic or abiotic factors involved in population abundance dynamics into niche models and (2) the need to establish specific monitoring protocols for tracking population dynamics.Despite the mounting evidence supporting positive relationships between species abundance and habitat suitability, the capacity of ecological niche models (ENMs) to capture variations in population abundance remains largely unexplored. This study focuses on sympatric populations of hen harrier (Circus cyaneus) and Montagu’s harrier (Circus pygargus), surveyed in 1997 and 2017 in an upland moor area in northwestern Spain. The ENMs performed very well for both species (with area under the ROC curve and true skill statistic values of up to 0.9 and 0.75). The presence of both species was mainly correlated with heathlands, although the normalized difference water index derived from Landsat images was the most important for hen harrier, indicating a greater preference of this species for wet heaths and peat bogs. The findings showed that ENM-derived habitat suitability was significantly correlated with the species abundance, thus reinforcing the use of ENMs as a proxy for species abundance. However, the temporal variation in species abundance was not significantly explained by changes in habitat suitability predicted by the ENMs, indicating the need for caution when using these types of models to infer changes in population abundance.

The purpose of this chapter is to examine the use of Information and Communication Technology (ICT) and mixed technology as ontology for self and distance learning in the state of Meghalaya in North East India. The points of reference are the population of the state, the men/women ratio, gender ratio of learners, the tele-density of the state, the number of colleges and the rural urban divide. Data and statistics are taken from secondary sources. The chapter highlights the specific use of mixed technologies to address the new breed of learners today; a hybrid of text and hypertext; the digital learner, with his or her penchant for technology; and the mobile phone. Distance education is now gradually merging with online ontology of teaching/learning. The chapter has come up with suggestions for improving delivery of educational services in the state of Meghalaya in North East India. The originality/value of this chapter lies in the cross currents of using technology for learning in the mid of the rural urban divide, strongly advocating the course of digital learners in a state of India besotted with poor road connectivity and envisaging mixed technologies: the computer, radio and the mobile phone as integrated methods of learning.

Large mammalian carnivores are threatened by anthropogenic environmental impacts, particularly through habitat loss which often cause population declines. Understanding the extent of suitable habitat is therefore of great importance for carnivore conservation. The leopard (Panthera pardus) is a widespread and relatively common large carnivore, but the species is declining in large parts of its range. Using maximum entropy‐based habitat models, we estimated the extent of suitable leopard habitat inSouthAfrica, what variables that are associated with suitable leopard habitats, the extent of habitat that has been negatively impacted by human activity and the effectiveness of protected areas to capture suitable habitat. Suitable leopard habitat was highly fragmented. Although vegetation and physical variables were the most influential variables for habitat suitability, livestock farming primarily seem to underlie fragmentation. We suggest that the sustainability of theSouthAfrican leopard population depends on maintaining dispersal routes between areas with suitable habitat. This will require mitigation of human–carnivore conflict in habitat corridors, particularly mitigation strategies targeting conflict between carnivores and livestock farmers. Because most suitable habitat occurred outside of protected areas, we also recommend that leopard conservation efforts should focus on areas that are not legally protected.

PDF HTML阅读 XML下载 导出引用 引用提醒 普洱市亚洲象栖息地适宜度评价 DOI: 10.5846/stxb201411142260 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金会资助项目（31172108）；美国内政部鱼和野生动物管理局亚洲象保护基金资助项目（98210-8-G565） Habitat suitability assessment for Asian elephant in Pu'er prefecture in the Yunnan province of China Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:亚洲象（Elephas maximus）属于我国Ⅰ级保护动物，在中国仅分布于云南省西双版纳国家级自然保护区、普洱市的思茅区、澜沧县和江城县，以及临沧南滚河国家级自然保护区。将普洱全境作为研究区域，利用野外调查数据，结合遥感与地理信息系统技术，运用生态位因子分析（ENFA）模型对普洱市亚洲象的栖息地适宜度进行了评价，并预测了适宜栖息地的分布。发现：普洱市亚洲象栖息地的边际值为0.991，表明亚洲象在普洱市境内对环境变量的选择不是随机的；耐受值为0.315，表明亚洲象在普洱市境内生态位较窄，受环境条件的制约。根据模型计算得到的栖息地适宜度指数，将普洱市的亚洲象栖息地分为最适栖息地，较适栖息地，边际栖息地和非栖息地4个等级，面积分别为409.32、574.32、2909.48、38722.32 km2。最适栖息地仅占全市面积的0.96%，而非栖息地占90.86%。利用GIS和Biomapper 4.0生成亚洲象栖息地分布图，发现普洱境内最适栖息地和较适栖息地面积狭小。对最适栖息地、较适栖息地和边际栖息地进行景观格局分析的结果表明，3种类型的栖息地破碎化均十分严重，连通度较低，栖息地内受到较大程度的人类活动的干扰。因此建议在普洱和西双版纳间尽快建立野生动物生态廊道，以加强亚洲象各种群间的交流。 Abstract:The Asian elephant (Elephas maximus) is listed as a first-class protected species in China, and is only distributed in Xishuangbanna, Pu'er, and Lincang prefectures of Yunnan Province. The main threats to the survival of elephants in China were habitat loss and fragmentation. Only 5 elephants were reported in Pu'er in 1996, and currently, there are over 80 elephants belonging to 8 groups living in the region. In this study, we collated 152 elephant occurrence points within the entire Pu'er range in 2010, and assessed habitat suitability for Asian elephant in Pu'er, based on Ecological Niche Factor Analysis (ENFA) of the field survey data. We also predicted the distribution of suitable habitats for elephants in Pu'er. The marginality value obtained from ENFA was 0.992. This result indicated that the deviation of the preferable niche of elephants was different from the average value of the environment, and that elephants chose their habitat non-randomly. The tolerance value was 0.315, which indicated that the niche of Asian elephant was narrow, and that environment indicators restricted the survival of elephants. Results showed that the elephants in Pu'er preferred natural forest with low elevation (<1419 m) and moderate slopes (<14°), as well as areas far from streams and human disturbance (villages and roads). We divided elephant habitat in Pu'er into 4 categories: optimal habitat (409.32 km2), suitable habitat (574.32 km2), marginal habitat (2909.48 km2), and unsuitable habitat (38722.32 km2). The unsuitable habitat accounted for 90.86% of the total area, whereas the optimal habitat occupied only 0.96%. Natural forest is the major vegetation type in optimal (55.6%), suitable (54.55%), and marginal (48.21%) habitats, but it constituted only 33.05% of the unsuitable habitat, indicating that natural forest is the preferred habitat for Asian elephants. According to landscape structure analysis using FRAGSTATS, the mean patch fractal dimension indices (FRAC_MN) for marginal, suitable, and optimal habitats were found to be close to 1, and the meancontiguity indices (CONTIG_MN) were found to be 0.12-0.15. Landscape analysis showed that the optimal, suitable, and marginal habitats all suffered severe fragmentation, low connectivity, and high levels of human disturbance. In comparison with real distribution, the predicted map incorporated some farmlands where Asian elephants forage. The proportion of optimal and suitable habitat in Pu'er is very low, owing to the loss of natural forest and the cultivation of economic plants. It is critical to establish protected areas in the habitat of Asian elephants, in combination with effective conservation measures. In addition, the three main areas of elephant distribution in Pu'er are isolated. It is understood that low connectivity among populations impedes important communication among different population groups. Therefore, it is also necessary to establish and restore ecological corridors to link the current elephant habitats in Pu'er, and to increase their connection with other elephant populations in Xishuangbanna. 参考文献 相似文献 引证文献

Globalization has undoubtedly emerged as one of the leading characteristics of the contemporary world. On the one hand, it has ushered in a new and promising era marked by rapid movements of large volumes of money and the increased volume of trade and has led to a growing density of market relations resulting in faster growth and creating unprecedented new opportunities for sustainable development and poverty reduction. At the same time, it also implies increased risk, uncertainty and vulnerability because of the widely fluctuating flows of capital around the globe and unstable exchange rates. In the context of the above, the paper proposes to examine the situation in Meghalaya, a state located in North East India and argues that globalization which entails greater interaction among cultures has generated a feeling of insecurity among the indigenous population, thereby consolidating the urge for preserving the indigenous culture from being invaded by the powerful waves of globalization. Globalization has undoubtedly led to increased transnational flows such as migration. The enhanced volume of migration has already unleashed the forces of ethnic backlash in most states of northeast India. In the context of the above, the paper will focus on the impact of greater global investment possibilities and migration of labor on local communities in Meghalaya in terms of the perceptions of regional political parties and local pressure groups. It will also examine the contradictions arising out of the desire to explore opportunities to capture the benefits of globalization on the one hand and the compulsion to protect local identities and heritage on the other. The paper has been divided into five sections. The first section focuses on the development constraints in northeast India and the difficulties in the land acquisition process. The second section highlights the global investment potential in Meghalaya and examines local resistance to the same. The next section discusses some initiatives taken by the Government of Meghalaya to attract investment. The fourth section examines local perspectives on uranium mining in Meghalaya. The fifth section comments on the impact of migration in northeast India as a whole and Meghalaya in particular. The fifth and the final section summarize the concluding observations of the paper in terms of the contradictions emanating from the parallel processes of globalization and local protest movements.

Ecological analysis of a cluster of Villages emphasising land use of different tribes in Meghalaya in North-east India

Background: Dalbergia latifolia and Dillenia pentagyna are medicinally significant tree species threatened by habitat loss and climate change. Identifying their current and future suitable habitats is crucial for conservation planning. Methods: We used Maxent (version 3.4.1) ecological niche modelling with 260 occurrence points and 19 bioclimatic variables from the WorldClim dataset to predict the potential distribution of these species in India. Seventy-five percent of the data were used for model training and 25% for testing, with 10 replicates under cross-validation. Future distribution under the 2050 A2a emission scenario was modelled using downscaled climate projections. Results: Maxent performed well, yielding high AUC values of 0.91 for D. latifolia and 0.938 for D. pentagyna, indicating strong predictive performance. The Western Ghats and parts of Central India emerged as the most suitable habitats. Key climatic predictors included minimum temperature of the coldest month and precipitation of the wettest month. Current suitable habitats were estimated at 111,242 km² for D. latifolia and 176,238 km² for D. pentagyna, while future projections indicated a reduction of 38.86% and 40.90% in suitable areas, respectively. Conclusions: Climate change is likely to significantly reduce the suitable habitat for both species by 2050. Conservation strategies should prioritize areas identified through modelling for both in-situ and ex-situ conservation efforts. Ecological niche modelling, as demonstrated here, is a powerful tool for guiding future habitat management and conservation of threatened species.

Climate and land cover change are critical drivers of avian species range shift. Thus, predicting avian species' response to the land and climate changes and identifying their future suitable habitats can help their conservation planning. The common pheasant (Phasianus colchicus) is a species of conservation concern in Iran and is included in the list of Iran's protected avian species. The species faces multiple threats such as habitat destruction, land cover change, and overhunting in the country. In this study, we model the potential impacts of future climate and land coverchange on the habitat suitabilityof common pheasant (Phasianus colchicus) along elevational gradients in Mazandaran province in Iran. We used shared socioeconomic pathways (SSP) scenarios and the 2015-2020 trend to generate possible future land cover projections for 2050. As for climate change projections, we used representative concentration pathway (RCP) scenarios. Next, we applied current and future climate and land cover projections to investigate how habitatsuitabilityofcommon pheasant willchange between 2020 and 2050 using species distribution modeling (SDM). Our results show that the species has 6000 km2 suitable habitat; however, between 900 and 1965 km2 of its habitat may be reduced by 2050. Furthermore, we found that the severity of the effects of climate and land cover change varies at different altitudes. At low altitudes, the impact of changing land structure is superior. Instead, climate change has a critical role in habitat loss at higher altitudes and imposes a limiting role on the potential range shifts. Overall, thisstudy demonstrates the vital role of land cover and climate change in better understanding the potential alterations in avian distribution.

Predicting Naegleria fowleri freshwater habitat suitability in the United States for the present-day and future using ecological niche modeling.

Aim While niche models are typically used to assess the vulnerability of species to climate change, they have been criticized for their limited assessment of threats other than climate change. We attempt to evaluate this limitation by combining niche models with life‐history models to investigate the relative influence of climate change and a range of fire regimes on the viability of a long‐lived plant population. Specifically, we investigate whether range shift due to climate change is a greater threat to an obligate seeding fire‐prone shrub than altered fire frequency and how these two threatening processes might interact.Location Australian sclerophyll woodland and heathland.Methods The study species is Leucopogon setiger, an obligate seeding fire‐prone shrub. A spatially explicit stochastic matrix model was constructed for this species and linked with a dynamic niche model and fire risk functions representing a suite of average fire return intervals. We compared scenarios with a variety of hypothetical patches, a patch framework based upon current habitat suitability and one with dynamic habitat suitability based on climate change scenarios A1FI and A2.Results Leucopogon setiger was found to be sensitive to fire frequency, with shorter intervals reducing expected minimum abundances (EMAs). Spatial decoupling of fires across the landscape reduced the vulnerability of the species to shortened fire frequencies. Shifting habitat, while reducing EMAs, was less of a threat to the species than frequent fire.Main conclusions Altered fire regime, in particular more frequent fires relative to the historical regime, was predicted to be a strong threat to this species, which may reflect a vulnerability of obligate seeders in general. Range shifts induced by climate change were a secondary threat when habitat reductions were predicted. Incorporating life‐history traits into habitat suitability models by linking species distribution models with population models allowed for the population‐level evaluation of multiple stressors that affect population dynamics and habitat, ultimately providing a greater understanding of the impacts of global change than would be gained by niche models alone. Further investigations of this type could elucidate how particular bioecological factors can affect certain types of species under global change.

BackgroundAs the climate warms, many species of reptiles are at risk of habitat loss and ultimately extinction. Locations of suitable habitat in the past, present, and future were modeled for several lizard species using MaxEnt, incorporating climatic variables related to temperature and precipitation. In this study, we predict where there is currently suitable habitat for the genus Pogona and potential shifts in habitat suitability in the past and future.MethodsGeoreferenced occurrence records were obtained from the Global Biodiversity Information Facility, climate variables (describing temperature and precipitation) were obtained from WorldClim, and a vegetation index was obtained from AVHRR satellite data. Matching climate variables were downloaded for three different past time periods (mid-Holocene, Last Glacial Maximum, and Last Interglacial) and two different future projections representative concentration pathways (RCPs 2.6 and 8.5). MaxEnt produced accuracy metrics, response curves, and probability surfaces. For each species, parameters were adjusted for the best possible output that was biologically informative.ResultsModel results predicted that in the past, there was little suitable habitat for P. henrylawsoni and P. microlepidota within the areas of their current range. Past areas of suitable habitat for P. barbata were predicted to be similar to the current prediction. Pogona minor and P. nullarbor were predicted to have had a more expansive range of suitable habitat in the past, which has reduced over time. P. vitticeps was predicted to have less suitable habitat in the past when examining the region of their known occurrence; however, there was predicted growth in suitable habitat in Western Australia. Both 2070 models predict a similar distribution of habitat; however, the model produced using the 2070 RCP 8.5 climate change projection showed a larger change, both in areas of suitable habitat gain and loss. In the future, P. henrylawsoni and P. microlepidota might gain suitable habitat, while the other four species could possibly suffer habitat loss.DiscussionBased on the model results, P. henrylawsoni and P. microlepidota had minimal areas of suitable habitat during the Last Glacial Maximum, possibly due to changes in tolerance or data/model limitations, especially since genetic analyses for these species suggest a much earlier emergence. The predicted late Quaternary habitat results for all species of Pogona are conservative and should be compared to the fossil record which is not possible at the moment due to the current inability to identify fossil Pogona to the species level. P. nullarbor and P. vitticeps future models predict substantial habitat loss. P. nullarbor could potentially be considered vulnerable in the present since it already has a restricted range, and a conservation plan may need to be considered.

Multi-scale effects of land cover and urbanization on the habitat suitability of an endangered toad

Hammerhead sharks (Sphyrnidae) of southeast Queensland: habitat and movements